Thrower board with magnetic spur and method of using the same

ABSTRACT

A spear-throwing apparatus including a spear-thrower with a magnet spur, the projecting end of which extends substantially along the body of the spear-thrower. The spear-thrower may contain a recessed loading groove to receive a spear shaft (projectile) that has a socket with a metallic element embedded in it to receive the magnet spur. During use, the magnetic spur connects magnetically to the embedded metal element to join the spear-thrower and the spear shaft with enough force to be suspended without a need for force or pressure from a practitioner.

TECHNICAL FIELD

The present invention relates to a spear-throwing device and, more particularly, to a thrower board with a magnetic spur.

RELATED ART

First devices used to throw darts or spears were developed by prehistoric populations throughout the world. It is unknown exactly where such devices originates, but archaeological evidence demonstrates that people used such devices as early as the Pleistocene (Ice Age). The apparent purpose of the thrower devices (or thrower boards) of various sorts that are activated by arm, for example, is to lengthen the arm, thereby adding a mechanical advantage in comparison to the situation when a spear is thrown with a bare hand—this facilitates the activation of the throw with grater force with less power provided by the arm and allows the spear to fly farther and potentially faster. Interest in throwing devices—and in particular in a spear-thrower—experienced a surge in the last couple of decades. While modern sporting use of spear-throwers is varied and often eccentric, such use remains one of the pleasures of the sport and facilitates making and trying out new gear.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a component of the spear-thrower system (that is, components of the projectile system), a projectile system assembly, and methods for forming and using of such components and assembly. The components include a projectile itself (which may be interchangeably referred to herein as a projectile shaft, a spear, arrow, or dart) and a projectile support body (or thrower board, or board, or spear thrower—these terms may be used interchangeably) configured to accommodate and support the projectile before launch. The projectile support board is equipped with a magnetic spur that corresponds to a judiciously disposed on the projectile shaft metallic element. The magnetic spur and the metallic element are spatially aligned, when the projectile shaft is disposed on the projectile support board, to come to physical and magnetic contact at a small area (in one case—a tip or projection of the spur) to aid in securing the projectile shaft in its rest position on the projectile support board. The magnet-caused connection between the spur and the metallic element of the projectile shaft allows the projectile shaft (the spear) and the support board (the spear thrower) to be joined with a force sufficient enough to keep the spear on the spar thrower without the user's effort to additionally restrain the spear (such as, for example, with the use of force applied by the user's fingers to keep the spear in place prior to launch). In one implementation, when the projectile system is assembled for launch, the spear is positioned along the support body such that projection of the spur at the proximal end of the support board is inserted into a concavity at the proximal end of the spear while magnetically bringing the two into contact. During use (at launch of the projectile), the assembly is engaged in forward motion with a force sufficient to overcome the magnetic force between the spur and the metallic element of the spear, and to separate the two releasing the spear from the projectile support body in the direction of the throw.

Accordingly, embodiments provide a projectile system that includes a projectile support body or thrower board having proximal and distal ends; a metallic spur juxtaposed with the support body at the proximal end and dimensioned to define a protrusion extending along the support body towards the distal end; and a projectile shaft having a first end corresponding to the proximal end and containing a socket at the first end. Here, the socket is dimensioned to accommodate a portion of the spur in the socket when the projectile shaft and the projectile support body are cooperated with one another to have the projectile shaft lie on the projectile support body. The socket includes a metallic element; and at least one of the metallic spur and the first end contains a magnet. Embodiments additionally provide a method of employing a projectile system. Such method includes a step of propelling or casting, in a forward motion, a projectile shaft disposed on a projectile support body (that has a proximal end, a distal end, and a metallic spur juxtaposed with the support body at the proximal end and dimensioned to define a protrusion extending along the support body towards the distal end) supporting said projectile shaft, while separating the projectile shaft from the projectile support body and, at the same time, maintaining physical contact and magnetic contact between a metallic element of a socket (disposed at a first end of the projectile shaft) and the protrusion (a portion of which is accommodated in the socket). Here, at least one of the metallic spur and the metallic element contains a magnet. The method further includes the step of ceasing such physical contact by separating the socket from the protrusion to fully release the projectile shaft. While setting the shaft in forward motion can be initiated by straightening the art and/or wrist of the user, a person of ordinary skill will appreciate that a similar motion can be started with an appropriate mechanical apparatus in which the projectile system is held in rest position prior to launch.

Embodiments of the invention also include a methodology for fabrication of a throwing device that is configured for throwing an elongated object rested on the throwing device. This method includes fabricating an elongated body f the device having distal and proximal ends and dimensioned to support the elongated object that contains a socket at a proximal end of the elongated object (with the metallic element contained in or at such socket) and that is rested on top of and along the body; (optionally-removably) attaching a spur containing a magnet to the proximal end of the body to establish a magnetic contact with the metallic element of the socket when, in operation of the device, the elongated object is disposed on top of the body and a protrusion of the spur is positioned in the socket in physical contact with the metallic element to magnetically bias the elongated object to remain in a rest position on top of the body until a sufficient force is applied to the object as a result of acceleration of the throwing device by a hand of the user.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood by referring to the following Detailed Description of Specific Embodiments in conjunction with the Drawings, of which:

FIG. 1 illustrates a portion of an embodiment of the invention;

FIG. 2 shows the embodiment of FIG. 1 in full length;

FIG. 3 depicts a portion of the embodiment of FIG. 1 without magnetic spur;

FIGS. 4 and 5 schematically illustrate portions of embodiments of a projectile configured according the idea of the invention;

FIG. 6 illustrates a principle of cooperation between the constituent components of an embodiment of the spear-throwing assembly (system) of the invention prior to launch of the spear;

FIG. 7 provides a top view of a portion of the spear-throwing system of FIG. 6;

FIG. 8 is a flow-chart addressing a method for utilizing an embodiment of the system of the invention.

Generally, the sizes and relative scales of elements in Drawings may be set to be different from actual ones to appropriately facilitate simplicity, clarity, and understanding of the Drawings. For the same reason, not all elements present in one Drawing may necessarily be shown in another.

DETAILED DESCRIPTION

A typical hand-driven version of a spear-thrower is, essentially, a beam or board (with or without a hook at the proximal end) that is shaped to engage the spear on one end and a grip for the hand near or at the other end. It allows the user to throw a spear considerably harder and farther than by hand alone by acting lie a lever, and appears to pre-date the use of the bow and arrow. In use, the spear is disposed onto the body of the spear-thrower and is supported by fingers at a location along the length of the spear to maintain its position. When initiating a throw, the user raises the spear-thrower with the spear on it level to the ground, aims at the target, steps forward and, with his torso rotated, flexes the arm at the shoulder (thus bringing the hand holding the spear-thrower and the spear forward). The throw is often completed by flexing the wrist to swing the spear-thrower and to flick the spear away—the motion is essentially the same as when throwing a baseball.

While various views exist on design of conventional spear-throwers exist, the inconclusive and contradictory results with experimental evaluations of spear-throwers make it difficult to evaluate some aspects of their use and comparison of efficiency of performance—“the hand-made gear is sometimes idiosyncratic” (see J. C. Whittaker, “Weapon Trials: The Altatl and Experiments in Hunting Technology”, available at web.grinnell.edu/anthropology/Faculty/JohnWhittaker/Articles/Atlatl%20Experiments.pdf).

Practically all thrower boards or spear-throwers known up to-date are structured such that—when the spear is located on the thrower board and before the user initiates the “throw” with his hand—the spear and the board must be maintained in mutual alignment with the hand of the user (often—with the use of fingers that hold or bring or push the spear towards and/or with respect to the board at a location between the distal and proximal ends of the board, thereby preventing the spear from “slipping off” the board and keeping it on and substantially parallel to the board). In other words, as a skilled artisan will readily appreciate, there has always been and remains a need to actively maintain the spatial cooperation between the spear and the thrower board in a conventionally-structured spear-thrower system at a location mid-way between the proximal and distal ends of the spear—starting from the moment of loading the spear on the board (when the physical contact between an element of the proximal end of the board and the proximal end of the spear is established while spear is supported by the board along a portion of the spear's length) and up to the moment of “swinging” the board to launch the spear. At the same time, at the moment of launch of the spear the user has to appropriately and timely release the grip on the spear to not impede its flight. The collective experience with conventionally-structured spear-throwing projectile systems begs a question: can the use of a projectile system be simplified?

The discussed below embodiments of the present invention address practical shortcomings caused, in use, by conventional designs of spear-throwing systems. In particular, the proposed structure of the constituent component of the embodiments increases the ease (with which a spear-throwing system can be operated by hand of the user) by substantially eliminating a need to maintain, by hand, the contact or affixation between the spear and the thrower board at a mid-way location of the spear. Understandably, the absence of such operational requirement during use of an embodiment of the invention, additionally eliminates the need to timely “release” the spear from the contact with the hand of the user. These and other operational advantages are realized by judicious formatting of the proximal ends of the thrower board and the spear (projectile) to establish a magnetic contact between the two. In particular, an appropriately-shaped magnet is cooperated with at least one of the proximal end of the spearthrower board and the proximal end of the spear, thereby removing additional levels of dexterity traditionally required by the practitioner. Moreover, as a person of skill will readily appreciate from the following disclosure, thus established magnetic connection provides and facilitates a rotational movement, of the spear, between the point of magnetic contact of the spear with the spearthrower board with a certain free range of angles. This allows the projectile to be “loaded” with ease without concerns of detachment from the thrower board if the thrower board is inadvertently moved or tilted or repositioned from the substantially horizontal position conventionally required for successful load o the spear on the board when a traditionally-structured spear-thrower system is used.

As broadly used and described in the description below and the accompanying claims, the following terms shall have the meanings indicated, unless the context requires otherwise:

The reference to a first element or component as being “carried” on a surface of another, second element refers to both such first component that is disposed directly on the surface of the second element and the first component that is disposed on yet another, third element that in turn is disposed directly on the surface of the second element.

The following disclosure describes embodiments of the invention with reference to the corresponding drawings, in which like numbers represent the same or similar elements wherever possible. In the drawings, the depicted structural elements and systems are not to scale and certain components are enlarged relative to the other components for purposes of emphasis and understanding. References throughout this specification to “one embodiment,” “an embodiment,” or similar language mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

To this end, schematic illustrations of one embodiment of the board 100 of the spear-throwing system are provided in FIGS. 1 and 2. FIG. 2 illustrates the board along its length, from the proximal end 104 to the distal end 108, while FIG. 1 provides an enlarged view of a proximal portion of the board 100. As shown, the board has an upper, typically substantially planar surface 112 (which, in operation of the board, supports the spear—now shown—at least along a portion of the length of the spear) and a generally optional loading groove 116 dimensioned to temporarily accommodate the proximal end of the spear during the loading process and to guide this proximal end of the spear towards the proximal end 104, until the proximal end of the spear comes into physical contact with the element at the end 104 configured as a stopper that stops and prevents the proximal end of the spear from moving further away from the distal end of the board 100. The spear (now shown) is then laid along the length of and on the board 100, and is additionally fixated in its position with the fingers of the user who holds the combination of the board 100 and the spear rested on it by the hand, with fingers extending around and above the board 100 and keeping the spear on the board at a location 120 between the ends 104, 108. (The location 120 is identified, in FIG. 2, with finger-accommodating indentations or notches 124 in the body 100; only one notch is visible in presented perspective view).

The proximal end 104 is equipped with a metallic spur element 130 (shown, in this specific embodiment, to be generally shaped as a polygonal plate of metal) that is affixed to the board 100 such as to direct a protrusion or “nose” or spur 130A of the spur element 130 backwards, to face the distal end 108. Optionally—and as illustrated in the specific example of FIGS. 1, 2—the metallic spur 130 is formatted to be removably affixed at the proximal end 104 with a chosen type of fastener (as shown—with the bolt/threaded rod/screw 134) to a surface of the board 100 that lies above the surface 112. In this case, once the spur 130 is affixed to the end 104, a gap is formed between the surface 112 and the lower surface of the spur element 130. Positioning of the spur 130 at the proximal end, understandably, may be subject to some variations. For example—and referring now also to FIG. 3—the spur element 130 may be disposed on a surface 310 defined by a bottom of the notch or cut 314, which is formed in the upper surface 140 of the proximal end 104 to accommodate the spur element 130 such that the upper surface of the spur is substantially flush with the surface 318 (that is, the body of the spur element 130 is inlaid in the proximal end once the spur is installed) while the non-zero spatial gap between the lower surface of the spur element 130 and the surface 112 is maintained. In a related embodiment (not shown), the spur element 130 may be affixed directly to the surface 140, such as to protrude above the surface 140. Alternatively or in addition, the spur may be simply glued (or otherwise permanently affixed) to the proximal end 104. In yet another related embodiment, the metallic spur can be dimensioned as a rivet or rod permanently or removably inserted into the proximal end 104 such as to extend along the body 110 toward the distal end 108 and be spatially separated from the surface 112.

In one implementation, the spur element 130 includes a magnet (for example, the plate of the spur can be completely formed from a magnetic material, or at least have the protrusion 130A made of such a material). In this case, the body of the spear—the spear shaft 400, schematically illustrated in FIG. 4—may be equipped with a reciprocating metallic element at its proximal end 404. In one implementation, such metallic element is formed by inserting a metallic bolt or screw 408 in a concavity or socket 410 formed at the end 404 of the otherwise non-metallic body of the shaft 400. In a related case, schematically illustrated in FIG. 5, the metallic shell-shaped element 508 such as a nail with a specifically-dimensioned shell-shaped head can be (optionally permanently) affixed to the proximal end 514 of the spear shaft 520 to define a concave metallic surface facing, along the axis of the shaft 520, away from the distal end of the shaft 520. The skilled artisan will appreciate other possible variations of implementation of this idea. In any case, the purpose of forming the metallic insert element at the proximal end of the shaft of the spear while, at the same time, defining a socket or concavity associated with such metallic insert element is to be able to establish both a physical and magnetic contact between the metallic insert element of the spear and the magnetic spur element 130 once the spear is loaded on the thrower board (such as the board 100, for example).

Notably, variations of the magnetic cooperation between the spear and the spear-thrower include the use of the spur of the thrower board and the metallic insert element of the spear both of which include magnets, or the use of the metallic insert element that includes a magnet while the spur of the thrower board is not a magnet but a magnetizable metal.

Portions of FIG. 6 schematically illustrates the spatial cooperation between the embodiment 520 of the spear (shown here with fletching elements 612) and the embodiment 100 of the thrower board (additionally equipped with loops 616 dimensioned to hold fingers of the user at or near the location 120). FIG. 7 schematically presents the spear 520 loaded onto the board 100 to be carried by the board 100, in magnetic and physical contact with the spur element 130, in top view.

In accordance with embodiments of the present invention, methods and spear-throwing apparatus and related methods are disclosed. One specific, non-limiting implementation addresses an apparatus that includes a polygonally-shaped (for example, a triangular) magnet spur, with or without an opening therethrough, dimensioned for insertion (for example, in an inlaid fashion, to be substantially flush with the surface of the spear thrower) in a similarly-shaped cutout or notch formed in the main body of the spear thrower.

The spearthrower in such specific implementation may contain a recessed loading groove to receive the spear shaft projectile. A skilled practitioner will appreciated that the groove formed in the support board serves as a guide for the rear socket of the projectile, allowing the projectile to slide along the groove to engage with the magnetic spur. This motion allows a more efficient, guided method of “reloading” the projectile. (Indeed, in cases where the spur is raised above/separated with a gap from the main body of the spearthrower, the practitioner has to bring the socket of the projectile to the exact location of the spur in order to “load” the projectile, which understandably complicates the loading process somewhat.) The spearthrower body must be manufactured materials capable of withstanding high amounts of tensile and compressive stress. The material must be semi-rigid, capable of small amounts of flexibility while returning to form. Hardwoods and dense thermoplastics such as polycarbonate may be used to construct the spearthrower. White oak and a 20% glass-filled polycarbonate, in another implementation, can also be use to provide balance of rigidity and flexibility: a thickness of about 6.0 mm to about 7.8 mm for a main body spearthrower in this case will suffice. When white oak is used, the thickness of the body of the spearthrower may be about 4.0 mm or so.

The distal point of the polygonally-shaped magnetic spur extends out into the recessed concavity of the loading groove of the spear thrower body. The spear shaft is equipped with a socket that contains a metallic element at a base of the socket and that is dimensioned to receive the magnet spur therein. During use, the (optionally inlaid) magnetic spur connects magnetically to the embedded metal insert in the socket of the spear shaft that has been loaded on top of the spear thrower to be carried by it. The connection between the magnetic spur and the metal insert allows the spear shaft and the main body of the spear thrower to be joined with enough force to have the spear suspended on the spear thrower without force or pressure applied by the practitioner or user. During use, the forward motion initiated by the practitioner provides sufficient force to cause the spear shaft to detach from the magnetic spur.

Embodiments of a spear of the invention require relatively lightweight materials for manufacture: the spear must be able to flex upon release to absorb the energy imparted by the practitioner without fishtailing, resulting in the loss of control and accuracy. Suitable spear materials encompass various materials associated with commercial arrow manufacture (such as hard and softwood dowels, carbon fiber, fiberglass, and aluminum, in some examples). The current model of spearthrower is paired with a compound spear made from two dowels joined by a stainless steel ferrule. The rear portion of the dart shaft is made from a 32″ long ⅜″ birch dowel. The front portion is made from a 34″ 7/16″ birch dowel. The projectile/spear tip is joined by a 11/32 socketed archery field point. Fletching includes several (for example, three) cut turkey feathers spaced at 120 degrees around the perimeter of the projectile shaft. In one case, an embedded screw of magnetically attractive steel occurs in the base of a concave socket at the rear of the shaft for attachment to the spearthrower spur.

In an embodiment where it is the spur that includes a magnet, such magnet must possess sufficient strength to provide a connection with the dart while in a throwing position. Examples of the magnetic materials for fabrication of the spur element include those including neodymium and/or samarium/cobalt.

A neodymium magnet of grade N50, for example, may provide optimum support for a 66″ length wooden birch projectile shaft.

FIG. 8 is a schematic flow-chart schematically illustrating a process of using an embodiment of the invention. Here, the projectile predisposed on a support board is accelerated and propelled from the support board, at step 820, while both the physical and magnetic contacts between the metallic element at the end of the projectile and the protrusion of the spur element of the support board is maintained. (Notably, preceding the disposition of the projectile on the support board, the spur may be—optionally removably-cooperated with the proximal end of projectile support board; see 810.) During such propelling—and when the projectile system is hand-held—either the arm and/or wrist of the user may be substantially straightened, or the projectile may be made to rotate about a point of contact between the metallic element and the spur, or both (steps 830 a, 830 b). Then, in a continued forward motion, the projectile is released from the support board while at least the magnetic contact between the metallic element and the spur is ceased; 840.

The described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. It is understood, however, that practical implementations of discussed embodiments may contain some or all of these features and, therefore, such coatings, interconnections, structural support elements, or auxiliary devices are implied in a particular drawing, unless stated otherwise, as they may be required for proper operation of the particular embodiment. In the preceding description, numerous specific details are recited to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, or materials.

For the purposes of this disclosure and the appended claims, the use of the terms “substantially”, “approximately”, “about” and similar terms in reference to a descriptor of a value, element, property or characteristic at hand is intended to emphasize that the value, element, property, or characteristic referred to, while not necessarily being exactly as stated, would nevertheless be considered, for practical purposes, as stated by a person of skill in the art. These terms, as applied to a specified characteristic or quality descriptor means “mostly”, “mainly”, “considerably”, “by and large”, “essentially”, “to great or significant extent”, “largely but not necessarily wholly the same” such as to reasonably denote language of approximation and describe the specified characteristic or descriptor so that its scope would be understood by a person of ordinary skill in the art. In one specific case, the terms “approximately”, “substantially”, and “about”, when used in reference to a numerical value, represent a range of plus or minus 20% with respect to the specified value, more preferably plus or minus 10%, even more preferably plus or minus 5%, most preferably plus or minus 2% with respect to the specified value. As a non-limiting example, two values being “substantially equal” to one another implies that the difference between the two values may be within the range of +/−20% of the value itself, preferably within the +/−10% range of the value itself, more preferably within the range of +/−5% of the value itself, and even more preferably within the range of +/−2% or less of the value itself

The use of these terms in describing a chosen characteristic or concept neither implies nor provides any basis for indefiniteness and for adding a numerical limitation to the specified characteristic or descriptor. As understood by a skilled artisan, the practical deviation of the exact value or characteristic of such value, element, or property from that stated falls and may vary within a numerical range defined by an experimental measurement error that is typical when using a measurement method accepted in the art for such purposes.

Accordingly, the invention should not be viewed as being limited to the disclosed embodiment(s). 

1. A projectile system comprising: a projectile support board having proximal and distal ends, the proximal end having a recess in an upper surface of the board; a metallic plate affixed in the recess of the proximal end and dimensioned to define a spur as a protrusion of the metallic plate that extends along the projectile support board towards the distal end with upper surfaces of the metallic plate and the spur being substantially flush with the upper surface of the board; and a projectile shaft having a first end corresponding to the proximal end and containing a socket at the first end; wherein the socket is dimensioned to accommodate the spur therein and to partially surround the spur when the projectile shaft and the projectile support board are cooperated with one another to have the projectile shaft lie on the projectile support board; wherein the socket includes a metallic element therein; and wherein at least one of the spur and the first end contains a magnet.
 2. The projectile system according to claim 1, wherein at least one of the following conditions is satisfied: a) the spur is configured to be reversibly spatially-connected with the projectile support board via a threaded connection; b) the spur contains said magnet; and c) the protrusion extends substantially parallel to a surface, of the projectile support board, that carries the projectile shaft.
 3. The projectile system according to claim 2, wherein at least one of the following conditions is satisfied: i) the threaded connection is formed through the metallic plate; ii) a portion of a perimeter of said recess substantially coincides with a portion of a perimeter of the metallic plate.
 4. The projectile system according to claim 1, wherein the projectile support board is configured to contain a groove nearing or at the proximal end and substantially facing the protrusion, wherein the protrusion is spatially separated from a bottom of the groove.
 5. The projectile system according to claim 4, wherein a bottom surface of the protrusion is separated from a surface of the groove with a spatial gap to accommodate a portion of the socket in the groove when the projectile shaft and the projectile support board are cooperated with one another to have the projectile shaft lie on the projectile support board.
 6. The projectile system according to claim 1, wherein said metallic element at the first end of the projectile shaft protrudes through an outer surface of the projectile shaft.
 7. The projectile system according to claim 1, wherein said metallic element contains a thread.
 8. A method of employing a projectile system, comprising: in a forward motion, propelling or casting a projectile shaft disposed on a projectile support board that supports said projectile shaft and that has a proximal end, a distal end, and a metallic plate affixed in a recess in an upper surface of the support board at the proximal end and that is dimensioned to define a spur as a protrusion of the metallic plate extending along the support board towards the distal end such as to have upper surfaces of the metallic plate and the spur be substantially flush with the upper surface of the board, while separating the projectile shaft from the projectile support board and, at the same time, maintaining physical contact and magnetic contact between a metallic element of a socket and the protrusion, wherein the socket is disposed at a first end of the projectile shaft and a portion of the protrusion is accommodated by and inside said socket, wherein the metallic plate is made of a magnet and/or the metallic element contains a magnet; and ceasing said physical contact by physically separating the socket from the protrusion to fully release the projectile shaft.
 9. The method according to claim 8, comprising at least one of: 1) forming said forward motion by straightening of at least one of an arm and a wrist; and 2) in a continued forward motion, mutually rotating the projectile shaft and the projectile support board about a point of contact between the protrusion and an internal surface of the socket while maintaining physical contact between said magnet and a responsive one of the spur and the metallic element.
 10. The method according to claim 8, comprising: positioning the projectile shaft on the projectile support board while establishing a physical contact between said magnet and a responsive one of the spur and the metallic element.
 11. The method according to claim 10, wherein at least one of the following conditions is satisfied: a) said positioning includes accommodating a portion of the protrusion in the socket; and b) said positioning includes sliding the first end of the projectile shaft in the groove that is formed in a surface of the projectile support board at the proximal end, wherein a surface of the groove is spatially separated from a lower surface of the spur.
 12. The method according to claim 8, comprising removably attaching said metallic plate to the projectile support board such that a lower surface of the plate is positioned at a level below that of the upper surface of the board or reversibly separating said metallic plate from the projectile support board.
 13. A throwing device configured for throwing an elongated object rested on the throwing device, for use by a person who holds the throwing device in a hand, the device comprising: an elongated body of the device having distal and proximal ends and dimensioned to hold the elongated object rested on top of and along the body; a metallic plate made of a magnet and removably attached in a recess in an upper surface of the proximal end such as to have an upper surfaces of the metallic plate be substantially flush with the upper surface of the proximal end and a) to direct a protrusion of the plate along the body towards the distal end thereof and b) to magnetically bias the elongated object to remain in a rest position on top of the body due to magnetic interaction between the protrusion and an inner surface of a socket of the elongated object until a sufficient force is applied thereto as a result of acceleration of the throwing device by the hand.
 14. The throwing device according to claim 13, wherein: a) the plate is configured to be reversibly spatially-connected with the throwing device via a threaded connection formed transversely to the upper surface of the plate; and c) the protrusion extends substantially parallel to a surface, of the throwing device, that carries the elongated object in operation of the device.
 15. The method for modifying the elongated object for use with the device configured according to claim 13, the method comprising: disposing an element made of a magnetic material within the socket to be brought in magnetic and physical contact with the protrusion. 